This invention relates to a method and apparatus for controlling the displacement of a winning tool by a support arm adapted for universal movement while supported by the frame of a tunneling machine employed to release material from the heading face and form a tunnel having a desired profile. More particularly, the present invention relates to such a tunneling machine wherein the range of movement by the winning tool is limited to a desired tunnel profile in relation to a laser beam projecting along a desired tunnel heading and wherein the tunneling machine includes detector means for generating signals which are proportional to deviations and/or offsets of the tunneling machine to control the range of movement by the winning tool.
It is possible to limit the traversing motion of a winning tool while supported for universal pivotal movement on a support arm of a tunneling machine. The traversing motion of a winning tool must be limited so as to cut only a desired tunnel cross section along a desired tunnel heading. One suggestion was to use set-point values to the coordinates of the winning tool. The coordinates are in the form of signals produced by using a light-reflective barrier to scan a template or pattern which defines a geometrical outline that is similar to the desired tunnel profile. The signals corresponding to the set-point values are corrected by other signals corresponding to deviations of the tunneling machine from a set-point position. The correcting signals actually correspond to position deviations of the tunneling machine and/or translating movements by a receiver for a laser beam. The signals corresponding to the set-point values of the coordinates are corrected not only by signals corresponding to deviations of the tunneling machine but also by rotation of the template. One or more of the correcting signals have a magnitude which is equal but opposite to the translating motion required to align the receiver with the laser beam. In this way, the range of movement by the winning tool remains at the set-point position as defined by the laser beam. In this control system, the laser receiver or parts thereof are aligned by detecting the laser beam while the template is aligned by gravity only.
It has also been proposed to control a tunneling machine having a winning tool supported for universal movement by a support arm through the use of two gyroscopic systems both of which are situated in cross-sectional planes of the roadway in which the heading of the tunnel is to proceed. The gyroscopic systems are associated with devices to form signals proportional to the angular deviations and displacements to the position of the tunneling machine. These signals are used to correct the measured values to the coordinates of the winning tool. A template, similar to the desired tunnel cross section, is traced by a reflective-light barrier and a reciever surface to provide corresponding electrical signals. A final control device is driven in response to the signals from the receiver surface to slide and rotate both the template within its plane and the control device for the light barrier. In this system, the two gyroscopic systems detect the angular deviations of the tunneling machine and correct the measured coordinates of the winning tool. The receiver surface is used to detect parallel deviations of the tunneling machine and slidably displace the template together with the final control device for the light-reflective barrier. However, the gyroscopic systems also detect offsets of the tunneling machine in cooperation with the receiver surface so that such offsets are corrected by rotation of the template.